how do I pervent a char being input

[fire child]

I want to set up a output input to get a positive number

int hop;

cout << "What is the transmition range?" << endl;
cin  >> hop;
do{
    cout << "Invalid entery, no node can communicate." << endl 
      << "What is the transmition range?" << endl;
    cin  >> hop;
}while (hop =< 0);

it works fine if I put in a number but if I put in a letter or char (on accident) it just repeats forever, is there a way to prevent this?

[helios]

http://www.cplusplus.com/forum/articles/6046/